Aerosol valve construction for dispensing two fluids

ABSTRACT

A codispensing valve construction for small hand-held aerosol type dispensers, comprising a tubular valve housing characterized by concentric inner and outer walls, with an annular space between said walls. The annular space is partitioned into two compartments, and tubular projections on the housing connect such compartments respectively with the interiors of two separated containers which can have different liquids and also a propellant. An annular valve seat sealingly engages the top edges of the annular walls of the valve housing and is also engageable by a poppet-vavle or shoulder on a depressible valve stem which passes vertically through the center of the seat. The valve stem also has a resilient spool valve portion which rides in the bore of the inner one of the concentric walls and closes off two passages at the top of the inner wall when the valve stem is in the raised position. Thus the two compartments of the annular space, which contain separate liquids, are isolated from each other. When the valve stem (which is of the hollow type with a side inlet opening) is depressed, the poppet or shoulder thereof becomes disengaged from the valve seat and at the same time the spool valve uncovers the two openings in the inner concentric wall. As a consequence, the liquids contained in the two compartments are now permitted to flow under pressure into the bore of the inner concentric wall and thence out through the hollow valve stem. When discharge occurs, the two liquids can mix as they enter the inner concentric wall or else further downstream as they are forced out through the hollow portion of the valve stem.

tates Patent [1 1 Steirnan et al.

llnite 1 Oct. 23, 1973 AEROSQL VALVE CONSTRUCTION FOR DISPENSING TWO FLUIDS [75] Inventors: Wolf Steiman, Fairfield; Steven W.

Beres, Bridgeport, both of Conn.

[73] Assignee: VCA Corporation, Greenwich,

, Conn.

[22] Filed: June 15, 1971 [21] Appl. No.: 153,170

Primary ExaminerSamuel F. Coleman Assistant ExaminerNorman L. Stack, Jr. Att0rneyH. Gibner Lehmann and K. Gibner Lehmann [57] ABSTRACT A codispensing valve construction for small hand-held aerosol type dispensers, comprising a tubular valve housing characterized by concentric inner and outer walls, with an annular space between said walls. The annular space is partitioned into two compartments, and tubular projections on the housing connect such compartments respectively with the interiors of two separated containers which can have different liquids and also a propellant. An annular valve seat sealingly engages the top edges of the annular walls of the valve housing and is also engageable by a poppet-vavle or shoulder on a depressible valve stem which passes vertically through the center of the seat. The valve stem also has a resilient spool valve portion which rides in the bore of the inner one of the concentric walls and closes off two passages at the top of the inner wall when the valve stem is in the raised position. Thus the two compartments of the annular space, which contain separate liquids, are isolated from each other. When the valve stem (which is of the hollow type with a side inlet opening) is depressed, the poppet or shoulder thereof becomes disengaged from the valve seat and at the same time the spool valve uncovers the two openings in the inner concentric wall. As a consequence, the liquids contained in the two compartments are now permitted to flow under pressure into the bore of the inner concentric wall and thence out through the hollow valve stem. When discharge occurs, the two liquids can mix as they enter the inner concentric wall or else further downstream as they are forced out through the hollow portion of the valve stem.

5 Claims, 12 Drawing Figures PAIENIEUnms um memes SHEET 2 OF 3 INVENTORS STEVEN W. BERKS BY Wolf STE/MAN Z O A41VT AEROSOL VALVE CONSTRUCTION FOR DISPENSING TWO FLUIDS PERTINENT PRIOR ART U.S. Pat. No. 3,550,813 issued to Herbert G. Lehmann and entitled Hand-Held Dispenser For Mixing Fluids, dated Dec. 29, 1970.

BACKGROUND This invention relates to aerosol valve constructions such as are employed in small hand-held dispensers pressurized by a propellant liquid or gas, and more particularly to dispensers of this type wherein two liquids or fluids are normally kept separate, and are only mixed during use and discharge of the dispenser. A prior dispenser of this type, illustrated in U.S. Pat. No. 3,550,813, utilized a tubular valve housing of single wall thickness, having a side fitting or tubular portion in one wall whereby connection could be made to one container through such tubular portion and connection to another container made through a bottom opening in the valve housing. Vertically slidable in the valve housing was a shouldered valve stem, and either the stem or else the valve housing in conjunction with the stem was so-constituted as to separate the bore of the housing into two separate chambers one of which communicated with the side tubular portion and the other of which communicated with the lower opening in the valve housing. The upper end of the valve housing sealingly engaged a resilient valve seat which was also sealingly engaged by a poppet or shoulderportion of the vertically movable valve stem when the stem was in the raised position. The two compartments thus formed in the bore of the valve housing were kept separate, and the liquids therein were not permitted to mix or be discharged. When the valve stem was depressed, the partitioning means in the housing was rendered inoperative and theliquids in the two compartments of the housing could mix, and could also discharge through the hollow portion of the valve stem which was no longer sealingly engaged with the valve seat. While this arrangement was feasible and operated satisfactorily, it involved a rather complicated construction of the valve housing and the valve stem, which was more costly than ordinarily considered desirable due to the throw-away nature of aerosol valves of this type, which necessitates components and assemblies of the lowest possible cost.

Other types of mixing valves have also been proposed and produced, wherein two completely separate valve structures were provided, mechanically interconnnected for simultaneous operation and arranged to respectively control the liquids from two different containers. In still other mixing valves, rather complicated valving mechanisms were employed for the purpose of keeping separate the two liquids intended to be mixed during discharge. However, in addition to involving a considerable expense, these other prior mixing valves were-subject to malfunctioning and leakage or seepage of the two liquids when the dispenser was not in use, as for example during shipment and storage.

SUMMARY The above disadvantages of prior mixing valves, involvingrather costly componentsand assemblies, are obviated by the present invention. One object of the invention is to provide a novel and improved mixing type or codispensing aerosol valve construction which is characterized by extreme simplicity and low cost of components, especially the valve housing component and the depressible valve stem component, to the end that the overall cost of the valve is greatly reduced. A related object of the invention is the provision of an improved mixing type aerosol valve as above set forth, which is especially reliable in its operation and effective to maintain separate the two liquids which are intended to mix only during the discharge of the dispenser.

The foregoing objects are accomplished by a novel, double-wall tubular valve housing characterized by concentric inner and outer walls defining an annular space therebetween. The valve housing has partitioning webs which separate such annular space into two separate compartments. Vertically movable within the bore of the inner concentric wall is a valve stem which passes through an annular resilient valve seat which sealingly engages the upper ends of the concentric valve housing walls. The valve stem has a poppet or shoulder which sealingly engages the seat to control the discharge of the dispenser contents, and also has a spool valve portion slidable in the bore of the inner wall of the housing, which latter at its upper end is provided with inlet openings communicating with the two compartments or chambers. Normally such openings are closed by the spool valve portion of the valve stem. At its bottom end, the valve housing has tubular portions or nipples for connection with two separate containers, either directly or else by means of a dip tube, etc. By such construction, the valve housing can be readily molded in simple cavities, at a reduced cost. Also, the valve stem assemblage is capable of easy and economical molding whereby the entire overall cost of the mixing valve construction is held to a low figure which is compatible with requirements usually considered acceptable for throw-away type aerosol valves.

Other features and objects of the invention reside in the provision of an improved codispensing or mixing type aerosol valve as above set forth, which is especially reliable in its functioning, smooth-acting, and effective in preventing creeping or intermixing of the liquids normally desired to be kept separate. An additional feature of the invention resides in the provision of an improved mixing-type valve which is readily adaptable for use with various styles of collapsible bags, dip tubes, etc., in conjunction with a rigid outer pressurized container.

Still other features and advantages will hereinafter appear.

in the drawings illustrating several embodiments of the invention:

FIG. l is a vertical axial sectional view of a mixing type aerosol valve as provided by the invention, mounted on a pressurized aerosol can and connected with a collapsible interior bag in the can and with a diptube. The valve is shown in the non-discharging position.

FIG. 2 is a view like that of FIG. 1, but showing the valve being actuated and mixing and discharging the two liquids of the dispenser.

FIG. 3 is a top plan view of the valve construction, apart from the outer pressurized container of the dispenser.

FIG. 4 is a bottom plan view of the valve construction.

FIG. 5 is a vertical axial sectional view similar to that of FIG. 1 but showing a mixing type valve construction constituting another embodiment of the invention, in the non-discharging position.

FIG. 6 is a view like that of FIG. 5 but showing the valve construction in the discharging condition.

FIG. 7 is a top plan view of the valve construction of FIG. 5.

FIG. 8 is a bottom plan view of the valve construction of FIG. 5.

FIG. 9 is a fragmentary axial sectional view of the valve construction of FIGS. 5-8 taken in a plane at right angles to the plane of FIG. 5.

FIG. 10 is a horizontal section taken on the line 10-10 of FIG. 9.

FIG. 11 is a top plan view of the valve housing of the valve of FIGS. 5 through 10.

FIG. 12 is a side elevational view of the valve stem part of the valve of FIGS. 5 through 10.

Referring first to FIGS. 14, the improved valve construction illustrated therein comprises an annular resilient valve seat member 20 through which there extends an axially movable, fairly rigid plastic valve stem 22 that is vertically shiftable between an advanced or raised, non-discharging position and a depressed discharging position, said stem having a first valve shoulder or poppet 24 which is engageable with the underside of the valve seat member 20 to control the flow of liquid through the opening of the member. The stem 22 has a hollow discharge portion 26 provided with a bore 28, and has a lateral passage 30 communicating with the bore 28 and normally closed over by the inner peripheral wall of the valve seat 20 as seen in FIG. I. The lateral passage 30 is located in spaced-apart relation with respect to the underside of the valve seat 20 when the stem 22 is depressed, as illustrated in FIG. 2, thereby to enable a discharge to occur through the valve seat and the stem.

In accordance with the invention, on the valve stem 22 there is provided a second valve or shoulder 31 in the form of a resilient plastic spool valve member 32 (hereinafter referred to in the claims as a second valve shoulder) which is engageable with and disengageable from the valve seat 20 substantially simultaneously with the first valve shoulder 24. A novel tubular rigid plastic valve housing is also provided by the invention, designated generally by the numeral 34, said valve housing having inner and outer cylindrical and concentric walls 36, 38 respectively. The inner wall 36 at its bottom terminates in a transverse bottom wall 38, and at its top has a pair of inlet openings 40, 42 which are normally closed by the spool valve member 32 when the stem 22 is in the raised position of FIG. 1. The bore of the inner wall 36 provides a close sliding fit with the spool valve member 32, and the underside of the latter is engaged by one end of a helical compression coil spring 44 which also engages the bottom wall 38 of the valve housing, thus constituting a return spring for the valve stem 22.

The outer cylindrical wall 38 of the valve housing 34 has an exterior annular shoulder portion 46, and said portion together with the valve seat 20 are clamped in an inverted metal mounting cup 48 which has a central opening 50 through which the valve stem 22 is vertically movable. The upperends of the walls 36, 38 of the valve housing 34 sealingly engage the valve seat 20 under the clamping action of the mounting cup 48.

The valve housing 34 has a pair of partitioning walls 52 which divide the annular space between the concentric walls 36, 38 into two compartments 54 and 56.

At its bottom, the valve housing 34 has a pair of tubular depending portions or nipples 58, 60 communicating by means of passages 62, 64 respectively with the compartments 54, 56. The tubular portion 58 has attached to it a collapsible bag 66 by means of a neck portion 68 thereof, and the tubular depending portion 60 of the valve housing carries a dip tube 70.

The collapsible bag 66 and the dip tube 70 are contained in an outer pressurized container 72 which contains one of the liquids of the dispenser and also a gaseous or liquid propellant such as Freon (a registered trademark). The collapsible bag 66 contains the other liquid, which is kept separate from that in the outer container 72 but is subjected to the pressure within the outer container, as will be understood. The dip tube 70 communicates with the interior of the outer container 72 and can conduct liquid therefrom through the passage 64 into the semi-circular compartment 56 of the valve housing. Also, liquid from the collapsible bag 66 can be conducted through the passage 62 into the semicircular compartment 54. The two liquids and the compartment 54, 56 are kept from mixing by virtue of the presence of the spool valve 32 which closes the notches or openings 40, 42 in the inner wall 36 of the valve housing normally.

The operation of the mixing valve illustrated in FIGS. 1-4 can now be understood. Considering FIG. 1, the non-discharging position is indicated. The valve shoulder 24 tightly seals against the valve seat 20 and prevents all discharge from the container or dispenser. Also, the spool valve portion 32 closes the inlet openings 40, 42 and maintains separated the two different liquids in the compartments 54, 56. When the valve stem 22 is depressed, the valve shoulders 24 and 31 will become separated from the valve seat 20, and the side opening of the valve stem will be disposed below the valve seat 20. Also, the inlet openings 40, 42 will be uncovered and due to the pressure existing in the outer container 72, liquid from such container and from the collapsible bag 66 will be forced upward respectively through the opening 64 and 62 into the compartments 56, 54 and thence through the inlet opening 42, 40 to mix in the interior or bore of the inner wall 36. Such mixing liquid will also be forced through the side inlet 30 of the valve stem and out through the bore 28 of the stem and orifice or depress button 74 carried by the stem. Upon release of the depressingforce from the button 74, the valve return spring 44 will again raise a valve stem 22 to the closed sealing position of FIG. 1. Such discharging condition and position of the valve is illustrated in FIG. 2.

It will now be understood from the foregoing that I have provided an especially simple and effective mixing or codispensing valve wherein the novel valve housing 34 can be readily molded in simple mold cavities at an extremely low cost. Further, the valve stem 22 together with the additional spool valve member 32 can be readily molded of plastic in separate cavities whereby the entire cost of the valve assemblage is held to an especially low figure. By virtue of the sealing engagement of the upper edge portions of the valve housing walls 36, 38 no leakage can occur past the housing, and the sealing engagement of the spool valve 32 with the inlet openings 40, 42 prevents seepage or mixing of the liquids from the compartments 54, 56. In this connection, a small pressure equalizing bleed passage 76 is provided in the bottom wall 78 of the valve housing. This enables a pressure to exist within the inner concentric wall 36 of the housing, which pressure (of gas for example) will equalize the pressures existing in the compartments 54, 56 thereby reducing to a minimum the likelihood of any leakage of liquid through the inlet openings 40, 42 when the valve stem 22 is in its raised, nondischarging position.

Another embodiment of the invention is illustrated in FIGS. 5-12. As shown, a molded plastic valve housing 80 is provided, having concentric inner and outer walls 82, 84 respectively, the upper ends of said walls being sealingly engaged with an annular resilient plastic or rubber valve seat 86. A valve stem 88 is provided, having a pair of passages 90, 92 communicating with side inlet openings 94, 96 respectively. The valve stem 88 has a poppet or shoulder 98 sealingly engaged with the underside of the valve seat 86 for the non-discharging position of FIG. 5. On the valve stem 88 there is a resilient rubber spool valve member 100 which normally closes inlet openings 102 and 104 in the upper end of the inner wall of the valve housing. The valve housing 80 also has a pair of partitioning walls 106 which divides the annular space between the inner and outer walls 82, 84 into two compartments 108 and 110. The compartments 108, 110 communicate with flexible bags 112, 114 by means of tubular depending portions 116 and 118 respectively of the valve housing, which are received in neck portions of the bags. The valve assemblage is carried in an outer pressurized container 120, by means of an inverted metal mounting cup 122. A valve return spring 124 engages a shoulder of the spool valve 100 to normally retain the valve stem 88 in the raised, non-discharging position of FIG. 5. The spool valve 100 includes a sleeve disposed within the spring 124, and includes a flange engaged by the upper end of the spring 124 as viewed in FIG. 9, said sleeve and flange mounting the shoulder portion indicated by the lead line from the numeral 100. Within the inner concentric wall 82 of the valve housing 80 there are provided ribs or projections 126 and 128, and also upstanding arcuate posts 130, 132 for engaging diametrically opposite portions of the underside of the spool valve 100. The spaces between the posts 130, 132 and the ribs 128, 126 provide clearance for the valve return spring 24.

Referring to FIG. 12, the underside of the valving shoulder 98 on the stem 88 is provided with a pair of arcuate cut-outs 134. Also, the spool valve 100 (herinafter termed in the claims a second valve shoulder) is made especially resilient, as of relatively soft rubber or rubber-like composition. With such construction, the valve shoulder 98 has pressure points in the form of small lands 136 which tend to shift downward diametrically opposite portions of the spool valve 100 when the stem 88 is depressed. Other diametrically opposite portions of the spool valve 100 are maintained in sealing engagement with the valve seat 86 by the ribs 126, 128 and posts 130, 132 which engage the undersurfaces of the spool valve under pressure. In conseopenings 102, 104 will separate from the valve seat 86 whereas other diametrically opposite portions will remain sealingly engaged with the valve seat. In consequence, the liquids which are entering through the inlet openings 102, 104 will not mix within the inner concentric wall 82 of the valve housing, but instead will remain separated and flow respectively into the side inlet openings 94, 96 of the valve stem, and through the longitudinal passages 90, 92 of the valve stem. The mixing of such liquids will first occur within the depress button 74 during the discharging of the dispenser, as illustrated in FIG. 6.

Accordingly, it will be seen from the foregoing that I have provided a novel and improved mixing type valve construction for handling two liquids which are normally intended to be kept separate in a pressurized aerosol dispenser, wherein the mixing of the liquids need not occur within the valve housing or within the depressible valve stem, but instead can first occur in the discharge or depress button 74l, according to the embodiment of the invention illustrated in FIGS. 5-12. With the embodiment of FIGS. 1-4, the mixing of the liquids can occur within the inner wall 36 of the valve housing 34.

With both embodiments of the invention the valve housing can be readily economically molded and removed from simple mold cavities, the same being true of the valve stem and spool valve portion thereof. It will be understood that, with the embodiment of FIGS. 5-12 one of the bags 112, 114 can be replaced by a dip tube as illustrated in FIGS. 1 and 2. Also, the embodiment of FIGS. 1-4 can utilize two collapsible bags instead of one bag and a dip tube as illustrated. With both embodiments, an effective mixing of the two liquids is had only during discharge, whereas the liquids are maintained separate for the non-discharging condition of the dispenser. As seen in FIGS. 9-11, the valve housing can be provided with a bleed hole 140 to provide for equalization of pressures within and outside of the inner concentric wall 82 of the valve housing.

Variations and modifications are possible without departing from the spirit of the invention.

I claim:

1. A multiple valve constructionfor an aerosol device comprising, in combination:

a. an 'annular valve seat member,

b. an upright axially movable valve stem extending through said valve seat member and shiftable therein between first and second positions, said stem having a first valve shoulder engageable with one side of the seat member to control flow through the member,

c. said stem having a hollow discharge portion projecting from the other side of the seat member and adapted to extend through the member when the stem is in its second position, and having a lateral passage disposed in said hollow portion and communicating with the interior thereof,

d. said lateral passage being located below said one side of the valve seat member when the stem is in its second position,

e. an annular resilient seal comprising a second valve shoulder disposed on the stem, surrounding the first valve seat shoulder and engageable with and disengageable from the valve seat member substantially simultaneously with the first valve shoulder,

f. a tubular valve housing having a wall provided with a bore in which the second valve shoulder is slidably movable and against which the second valve shoulder seals,

g. said wall engaging said valve seat member, and having a pair of oppositely located inlet openings adjacent the seat member,

h. said inlet openings being closed by the second valve shoulder when the latter is in engagement with the valve seat member, and being opened by the shoulder when the stem is in its second position to separate portions of the second valve shoulder from the seat member,

. said stem when shifted to its second position disengaging at least portions of the shoulders thereof from the seat member and shifting the second shoulder away from the inlet openings of the housing wall whereby said openings can communicate with the lateral passage of the valve stem to permit flow from the exterior of the housing wall through said openings and through the hollow portion of the stem,

j. the bottom of the tubular valve housing having a bleed opening to enable limited communication between the interior and exterior of the housing at a point below said second valve shoulder,

k. said valve housing having a second wall surrounding, spaced from and concentric with the firstmentioned wall,

I. said second wall engaging and sealing against said valve seat member,

m. a pair of partitioning walls extending between the second wall and the first-mentioned wall and evenly dividing the space between the walls into two separate chambers, each of which is equal in volume to slightly less than one-half the total volume included between said walls,

n. a pair of separate pressure containers,

0. said valve housing having inlet openings communicating respectively with said chambers formed by said concentric walls and adapted to receive fluid under pressure respectively from said two separate pressure containers.

2. A multiple valve construction for an aerosol device comprising, in combination:

a. an annular valve seat member,

b. an upright axially movable valve stem extending through said valve seat member and shiftable therein between first and second positions, said stem having a first valve shoulder engageable with one side of the seat member to control flow through the member,

c. said stem having a hollow discharge portion projecting from the other side of the seat member and adapted to extend through the member when the stem is in its second position, and having a lateral passage disposed in said hollow portion and communicating with the interior thereof,

d. said lateral passage being located below said one side of the valve seat member when the stem is in its second position,

e. an annular resilient seal comprising a second valve shoulder disposed on the stem, surrounding the first valve shoulder and engageable with and disengageable from the valve seat member substantially simultaneously with the first valve shoulder,

f. a tubular valve housing having a wall provided with a bore in which the second valve shoulder is slidably movable and against which the second valve shoulder seals,

g. said wall engaging said valve seat member, and having a pair of oppositely located inlet openings adjacent the seat member,

h. said inlet openings being closed by the second valve shoulder when the latter is in engagement with the valve seat member, and being opened by the shoulder when the stem is in its second position to separate portions of the second valve shoulder from the seat member,

i. said stem when shifted to its second position disengaging at least portions of the shoulders thereof from the seat member and shifting the second shoulder away from the inlet openings of the housing wall whereby said openings can communicate with the lateral passage of the valve stem to permit flow from the exterior of the housing wall through said openings and through the hollow portion of the stem,

j. means a pair of opposite portions of the second valve shoulder, which are spaced from the inlet openings of the housing wall, permanently in engagement with the seat member to isolate from each other the flows through said inlet openings,

k. said first valve shoulder having a pair of oppositely disposed recesses in its underside,

l. a resilient sleeve and a flange connected to one end thereof, said sleeve and flange being integral with said second valve shoulder and mounting the same,

m. a coil spring on the stem, engageable with said flange and operable to yieldably hold the first and second valve shoulders in engagement with the seat member,

n. said flange underlying the first valve shoulder and being engageable therewith,

o. the recesses in the underside of the first valve shoulder providing clearance for portions of said flange, to enable the coil spring to maintain portions of the second valve shoulder in contact with said seat member at those times that the valve stem is depressed.

3. A valve construction as in claim 2, wherein:

a. the hollow portion of the valve stem has two longitudinal passages communicating respectively with the lateral passages thereof.

4. A valve construction as in claim 2, wherein:

a. said means for permanently holding portions of the second valve shoulder comprises projections in the bore of the housing wall, engaged with said shoulder portions and clamping the same against said valve seat member.

5. A valve construction as in claim 4, and further including:

a. a valve return spring engaged with the underside of the second valve shoulder and located between said projections in the bore of the housing wall,

b. said spring being compressed when the valve stem is in its second position, and acting to yieldably hold the stem in its first, non-discharging position. 

1. A multiple valve construction for an aerosol device comprising, in combination: a. an annular valve seat member, b. an upright axially movable valve stem extending through said valve seat member and shiftable therein between first and second positions, said stem having a first valve shoulder engageable with one side of the seat member to control flow through the member, c. said stem having a hollow discharge portion projecting from the other side of the seat member and adapted to extend through the member when the stem is in its second position, and having a lateral passage disposed in said hollow portion and communicating with the interior thereof, d. said lateral passage being located below said one side of the valve seat member when the stem is in its second position, e. an annular resilient seal comprising a second valve shoulder disposed on the stem, surrounding the first valve seat shoulder and engageable with and disengageable from the valve seat member substantially simultaneously with the first valve shoulder, f. a tubular valve housing having a wall provided with a bore in which the second valve shoulder is slidably movable and against which the second valve shoulder seals, g. said wall engaging said valve seat member, and having a pair of oppositely located inlet openings adjacent the seat member, h. said inlet openings being closed by the second valve shoulder when the latter is in engagement with the valve seat member, and being opened by the shoulder when the stem is in its second position to separate portions of the second valve shoulder from the seat member, i. said stem when shifted to its second position disengaging at least portions of the shoulders thereof from the seat member and shifting the second shoulder away from the inlet openings of the housing wall whereby said openings can communicate with the lateral passage of the valve stem to permit flow from the exterior of the housing wall through said openings and through the hollow portion of the stem, j. the bottom of the tubular valve housing having a bleed opening to enable limited communication between the interior and exterior of the housing at a point below said second valve shoulder, k. said valve housing having a second wall surrounding, spaced from and concentric with the first-mentioned wall, l. said second wall engaging and sealing against said valve seat member, m. a pair of partitioning walls extending between the second wall and the first-mentioneD wall and evenly dividing the space between the walls into two separate chambers, each of which is equal in volume to slightly less than one-half the total volume included between said walls, n. a pair of separate pressure containers, o. said valve housing having inlet openings communicating respectively with said chambers formed by said concentric walls and adapted to receive fluid under pressure respectively from said two separate pressure containers.
 2. A multiple valve construction for an aerosol device comprising, in combination: a. an annular valve seat member, b. an upright axially movable valve stem extending through said valve seat member and shiftable therein between first and second positions, said stem having a first valve shoulder engageable with one side of the seat member to control flow through the member, c. said stem having a hollow discharge portion projecting from the other side of the seat member and adapted to extend through the member when the stem is in its second position, and having a lateral passage disposed in said hollow portion and communicating with the interior thereof, d. said lateral passage being located below said one side of the valve seat member when the stem is in its second position, e. an annular resilient seal comprising a second valve shoulder disposed on the stem, surrounding the first valve shoulder and engageable with and disengageable from the valve seat member substantially simultaneously with the first valve shoulder, f. a tubular valve housing having a wall provided with a bore in which the second valve shoulder is slidably movable and against which the second valve shoulder seals, g. said wall engaging said valve seat member, and having a pair of oppositely located inlet openings adjacent the seat member, h. said inlet openings being closed by the second valve shoulder when the latter is in engagement with the valve seat member, and being opened by the shoulder when the stem is in its second position to separate portions of the second valve shoulder from the seat member, i. said stem when shifted to its second position disengaging at least portions of the shoulders thereof from the seat member and shifting the second shoulder away from the inlet openings of the housing wall whereby said openings can communicate with the lateral passage of the valve stem to permit flow from the exterior of the housing wall through said openings and through the hollow portion of the stem, j. means a pair of opposite portions of the second valve shoulder, which are spaced from the inlet openings of the housing wall, permanently in engagement with the seat member to isolate from each other the flows through said inlet openings, k. said first valve shoulder having a pair of oppositely disposed recesses in its underside, l. a resilient sleeve and a flange connected to one end thereof, said sleeve and flange being integral with said second valve shoulder and mounting the same, m. a coil spring on the stem, engageable with said flange and operable to yieldably hold the first and second valve shoulders in engagement with the seat member, n. said flange underlying the first valve shoulder and being engageable therewith, o. the recesses in the underside of the first valve shoulder providing clearance for portions of said flange, to enable the coil spring to maintain portions of the second valve shoulder in contact with said seat member at those times that the valve stem is depressed.
 3. A valve construction as in claim 2, wherein: a. the hollow portion of the valve stem has two longitudinal passages communicating respectively with the lateral passages thereof.
 4. A valve construction as in claim 2, wherein: a. said means for permanently holding portions of the second valve shoulder comprises projections in the bore of the housing wall, engaged with said shoulder portions and clamping the same against said valve seat member.
 5. A valve consTruction as in claim 4, and further including: a. a valve return spring engaged with the underside of the second valve shoulder and located between said projections in the bore of the housing wall, b. said spring being compressed when the valve stem is in its second position, and acting to yieldably hold the stem in its first, non-discharging position. 